CCD based emissivity measurements for surface characterization in heat treatment processes

Gerald Zauner; Gerald Darilion; Daniel Heim; G. Hendorfer; Thomas Mueller

doi:10.1117/12.612525

13 June 2005 CCD based emissivity measurements for surface characterization in heat treatment processes

Gerald Zauner, Gerald Darilion, Daniel Heim, G. Hendorfer, Thomas Mueller

Proceedings Volume 5856, Optical Measurement Systems for Industrial Inspection IV; (2005) https://doi.org/10.1117/12.612525
Event: Optical Metrology, 2005, Munich, Germany

Abstract

Plasma nitriding is an industrial surface hardening process which involves diffusion of nitrogen atoms into the metal surface to enhance material properties. The aim of this work is the development of a low cost device (based on a standard near infrared enhanced CCD camera) for the inline-characterization of such surface modifications during thermo-chemical heat treatment for improved process control. Due to relatively low process temperatures of about 400°C - 600°C the emitted light intensity of the heated metal parts is very weak. The imaging device therefore primarily utilizes the CCD-silicon’s spectral sensitivity for wavelengths around 1μm. As the emissivity of metals generally increases strongly at shorter wavelengths, the considered spectral range has certain advantages with regard to sensitivity for emissivity changes. Therefore, the measurement system is based on the principles of ratio pyrometry (dual-band-method), in which two images of the same scene, each taken at slightly different spectral bands, are used to determine the spectral light intensities. This results in an improved relative sensitivity for spectral changes (i.e. deviations from the gray-body hypothesis) which makes it possible to correlate the measured spectral intensities with surface modifications during the plasma nitriding process.

Citation Download Citation

Gerald Zauner, Gerald Darilion, Daniel Heim, G. Hendorfer, and Thomas Mueller "CCD based emissivity measurements for surface characterization in heat treatment processes", Proc. SPIE 5856, Optical Measurement Systems for Industrial Inspection IV, (13 June 2005); https://doi.org/10.1117/12.612525

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available